FIGS. 1A and 1B illustrates a known method of connecting a piston plate in a torque converter. In FIG. 1A, rivet 10 has been inserted in plate 12 and element 14, and head 16 of the rivet is in contact with cover 18. The cover rests on base 20 and fixture 22 is positioned to apply pressure to the rivet. Plate 12 is substantially parallel to portion 24 of the cover. In FIG. 1B, die 25 has pushed on plate 12 and element 14 to that the plate and element are pressed together against the rivet head. The fixture then applies pressure to the rivet to coin the rivet head. Plate 12 is still substantially parallel to portion 24 of the cover.
FIG. 1C illustrates blind riveting as disclosed in commonly owned U.S. Patent Application No. 61/253,181, filed Oct. 20, 2009. Plate 12 and element 14 have been displaced so that the rivet is in contact with the cover, but the plate and the element are no longer parallel to portion 24 and the rivet is no longer orthogonal to portion 24. Surface 26 of the rivet head does not align with portion 24; therefore, only portion 28 of the end surface is in contact with portion 24. As die 25 displaces to engage plate 12, the upper portion of the die will engage the plate before the lower portion does so, generating an uneven force on the plate. The fixture applies force to the rivet in direction D. Due to the gap between portion 24 and surface 26, the rivet pivots so that portion 24 aligns with surface 26, creating gap 32. Due to the preceding alignment, force is unevenly applied to the rivet head and uneven spreading of the rivet head, improper fill by body 30 of the rivet, damage to the rivet head, damage to the plate or element, or a change in the angle for the plate or element can occur, resulting is a less robust connection and possible leakage around the rivet.